Reversibly thermochromic composite fiber
To provide a reversibly thermochromic composite fiber having a reversible color change due to a temperature change, having such excellent flame retardancy that flame is hard to spread even if ignition occurs once, and having high safety. [Solution] Disclosed is a sheath-core type reversibly thermochromic composite fiber including a core comprising a resin, a reversibly thermochromic pigment, and a flame retardant, and a sheath comprising a resin and a flame retardant.
1. A sheath-core type reversibly thermochromic composite fiber comprising:
a core comprising a polyolefin-based resin, a reversibly thermochromic pigment, and a first flame retardant; and
a sheath comprising a polyolefin-based resin and a second flame retardant,
wherein the first flame retardant is a phosphorus compound, and the second flame retardant is a phosphorous compound, and
wherein the core comprises 2 to 4% by mass of the first flame retardant based on the total mass of the reversibly thermochromic composite fiber, and the sheath comprises 0.4 to 0.8% by mass of the second flame retardant based on the total mass of the reversibly thermochromic composite fiber.
2. The reversibly thermochromic composite fiber according to claim 1 , wherein an average outer diameter of the reversibly thermochromic composite fiber is 10 to 300 μm.
3. The reversibly thermochromic composite fiber according to claim 1 , wherein an average length of the reversibly thermochromic composite fiber is 5 to 600 mm.
4. The reversibly thermochromic composite fiber according to claim 1 , wherein an area ratio of the core: the sheath in a cross section of the reversibly thermochromic composite fiber is 4:6 to 7:3.
5. A head ornament comprising the reversibly thermochromic composite fiber according to claim 1 .
6. The head ornament according to claim 5 , wherein the head ornament is a hair wig or a hair extension.
7. A toy comprising the reversibly thermochromic composite fiber according to claim 1 .
8. The toy according to claim 7 , wherein the toy is a doll, an animal-figured toy, a stuffed animal, or an accessory thereof.